Answer:
<em>The change of momentum of the dart is 0.84 Nw.s</em>
Explanation:
<u>Impulse and change of momentum</u>
The change in momentum of an object is its mass times the change in its velocity:

The change in the momentum can also be found by considering the force acting on it. If a force F acts for a time Δt, the change of momentum is given by:

The dart hits a dashboard with a net force of 14 N during the collision and stops in 0.06 seconds. The change of momentum is:

The change of momentum of the dart is 0.84 Nw.s